<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        section {
            width: 1000px;
            height: 600px;
            /* background: palegreen; */
            margin: 100px auto;
            display: flex;
            border: 2px solid saddlebrown;
            /* flex-direction: row; 默认水平排列 */
            /* flex-direction: column;默认竖直排列 */
            /* flex-direction: row-reverse; */
            /* //水平翻转 就是倒过来了 */
            /* flex-direction: column-reverse;垂直翻转 */
            /* justify-content: space-between; */
            justify-content: space-evenly;
            align-items: stretch;
        }
        
        section div {
            width: 250px;
            /* height: 200px;  */
            /* order: -1; */
        }
        
        section div:nth-child(1) {
            background-color: palegoldenrod;
            /* width: 200px; */
        }
        
        section div:nth-child(2) {
            background-color: palegreen;
            /* width: 100px; */
            order: -1;
            /* 值越小，越在前面  */
        }
        
        section div:nth-child(3) {
            background-color: paleturquoise;
            /* flex: 1; */
        }
    </style>
</head>

<body>
    <section>
        <div>1</div>
        <div>2</div>
        <div>3</div>

    </section>
</body>

</html>